1. Field of the Invention
The present invention relates to a process for the production of coenzyme Q (hereinafter referred to as Co-Q) in high yields from tissues of animals and plants, or microbial cells, which contain Co-Q.
2. Description of the Prior Art
Co-Q occurs in mitochondria of animals and plant tissues, and microbial cells, and is known to play an important role in organisms as an essential factor in the terminal electron transport system. Many reports on the pharmacological and clinical effects of Co-Q have been presented, and remarkable effects on congestive heart failure, coronary insufficiency, muscular dystrophy caused by malnutrition, and anemia have been elucidated. Thus, its value as a medicine has recently increased.
The methods known for the extraction of Co-Q from natural sources include a direct saponification method in which materials containing Co-Q are directly saponified with an alcoholic alkali hydroxide in the presence of an antioxidant such as pyrogallol and thereafter Co-Q is extracted with a hydrophobic solvent such as n-hexane and purified by column chromatography.
In another method, the materials are first extracted, for example, with an organic solvent such as n-hexane, isooctane, acetone, and ethanol, then the extract or the concentrate is purified by column chromatography or saponified with an alcoholic alkali hydroxide in the presence of an antioxidant such as pyrogallol and then Co-Q is extracted with a hydrophobic solvent and purified (Japanese Pat. No. 404804). The direct saponification method, however, has disadvantages such as the necessity of expensive chemicals and the use of large amounts of solvents. On the other hand, in the latter method saponifiable substances such as neutral fats and phospholipids are extracted together with Co-Q. These impurities must be removed by saponifying the extract in the presence of an antioxidant or by complicated purification processes. This method, therefore, also has disadvantages such as high purification costs and low yields because of the use of an antioxidant and the employment of complicated processes.
The present inventors carried out investigations to improve the known methods and to establish a method for obtaining Co-Q in high yield and at a relatively low cost. The present inventors have found that Co-Q is stable to an alkali in water as will be described later. The present inventors further have found that after tissues of animals and plants or microbial cells which contain Co-Q are treated with an alkali, or with an acid and then an alkali, the treatment resulting in the hydrolysis of saponifiable substances such as neutral fats and phospholipids and the disruption of the tissues or cells so that Co-Q becomes readily extractable, non-saponifiable lipids containing Co-Q are obtained in high yields by liquid-liquid extraction with solvents which are separable from water.